THOUSAND OAKS, Calif. — In a year built around positive thinking, U.S. Open champion Michael Campbell had to dig deep yesterday after dropping four shots over his last four holes for an even-par 72 in the Target World Challenge.

"I've actually increased my lead by one shot," Campbell said.

But only because he wasn't alone in his struggles.

Campbell hit a 5-iron into the hazard on the 18th hole and made double bogey, but those trying to chase him also stumbled down the stretch at Sherwood Country Club, leaving him three ahead of Padraig Harrington and Darren Clarke.

Campbell, who tied the course record with a 63 on Thursday for a two-shot lead over Clarke, was at 9-under 135 heading into the weekend in the 16-man event that pays $1.3 million to the winner. Harrington (70) and Clarke (73) each bogeyed the 18th hole.

Kenny Perry was the only player who appeared capable of running with Campbell until he made bogey on the par-5 16th, then took double bogey on the final hole for a 70. He was at 139 with Fred Couples, who had a bogey-free 68.

Tournament host Tiger Woods butchered the par-5 11th and made double-bogey, and couldn't get anything else going in a round of 72 that left him at 144. Woods has either won or finished second since his tournament moved to Sherwood in 2000.

ELSEWHERE

Lexus Cup: Annika Sorenstam and American teenager Paula Creamer made five birdies to beat Jeong Jang and Meena Lee, 2 and 1, in alternate-shot play to help the International team take a 4-2 lead over Asia after the first day of the Lexus Cup in Singapore. The first team to 11 1/2 points after today's fourball competition and tomorrow's singles matches wins.

Australian Masters: Australia's Nick O'Hern shot a 6-under 66 for a 14-under 130 total and a five-stroke lead over Australian Open and PGA winner Robert Allenby (68), and American Bubba Watson (65) after the second round of the Australian Masters in Melbourne.

Dunhill Championship: South Africa's Michiel Bothma took a one-stroke lead in the suspended second round of the rain-interrupted Dunhill Championship, finishing off an 8-under 64 in the first round and adding a 71 in the second at Nelspruit, South Africa.